What is the pH of a solution made by dissolving 0.1 moles of NaOH and 0.2 moles of HCl in 2 L of water?

pH = 1.30

Explanation:

The reaction that would take place between HCl and NaOH is:

In this problem, the 0.1 moles of NaOH would react with 0.1 moles of HCl, leaving 0.1 moles of HCl unreacted.

These 0.1 HCl moles are dissolved in 2 liters, thus the concentration of H⁺ species is:

Finally we calculate the pH:

answer: c. the experiment shows that the red substance experienced a chemical change.

explanation: chemical change is the change in which chemical composition of the substance changes. physical change is the change in which there is no change in chemical composition.

chemical changes are accompanied by following changes:

a) precipitate formation

b) energy is released or absorbed

c) formation of bubbles

d) change in color

as it is given that the red color has disappeared and there is production of gas, it means the red substance has undergone a chemical change.

e